is the extra damping from the FRM-driven spin current. It is more convenient to define the spin-mixing
conductance per area \(g^{\uparrow \downarrow }=G^{\uparrow \downarrow }/A\) , and, for YIG films, typical spin-mixing conductance
values are found over the interval \(1.1-3.9\times 10^{18} m^{-2}\) , while \(\eta _0\sim 10^{-3}\) ,
depending on geometric and intrinsic sample properties [1]}, [2]}, [3]}.
